=over

=item $SUBSCRIPT_SEPARATOR

=item $SUBSEP

=item $;
X<$;> X<$SUBSEP> X<SUBSCRIPT_SEPARATOR>

The subscript separator for multidimensional array emulation.  If you
refer to a hash element as

    $foo{$x,$y,$z}

it really means

    $foo{join($;, $x, $y, $z)}

But don't put

    @foo{$x,$y,$z}	# a slice--note the @

which means

    ($foo{$x},$foo{$y},$foo{$z})

Default is "\034", the same as SUBSEP in B<awk>.  If your keys contain
binary data there might not be any safe value for C<$;>.

Consider using "real" multidimensional arrays as described
in L<perllol>.

Mnemonic: comma (the syntactic subscript separator) is a semi-semicolon.

=back